Loans and Allowance for Credit Losses (Details 1) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Allowance for Credit Losses, beginning balance	$ 65,807	$ 59,848	$ 64,758	$ 59,074
Loans charged-off	(925)	(973)	(2,031)	(1,673)
Recoveries of loans previously charged-off	77	606	263	683
Net loans charged-off	(848)	(367)	(1,768)	(990)
Provision for credit losses	1,650	1,566	3,619	2,963
Allowance for Credit Losses, ending balance	66,609	61,047	66,609	61,047
Individually evaluated for impairment	8,629	5,925	8,629	5,925
Collectively evaluated for impairment	57,980	55,122	57,980	55,122
Commercial [Member]
Allowance for Credit Losses, beginning balance	13,358	14,583	13,102	14,700
Loans charged-off	(408)		(1,261)	(137)
Recoveries of loans previously charged-off	23	255	26	268
Net loans charged-off	(385)	255	(1,235)	131
Provision for credit losses	(767)	(613)	339	(606)
Allowance for Credit Losses, ending balance	12,206	14,225	12,206	14,225
Individually evaluated for impairment	4,506	3,070	4,506	3,070
Collectively evaluated for impairment	7,700	11,155	7,700	11,155
Income Producing - Commercial Real Estate [Member]
Allowance for Credit Losses, beginning balance	26,468	21,384	25,376	21,105
Loans charged-off		(970)	(121)	(1,470)
Recoveries of loans previously charged-off	2		2	50
Net loans charged-off	2	(970)	(119)	(1,420)
Provision for credit losses	1,518	2,894	2,731	3,623
Allowance for Credit Losses, ending balance	27,988	23,308	27,988	23,308
Individually evaluated for impairment	3,543	2,013	3,543	2,013
Collectively evaluated for impairment	24,445	21,295	24,445	21,295
Owner Occupied - Commercial Real Estate - [Member]
Allowance for Credit Losses, beginning balance	5,471	4,026	5,934	4,010
Loans charged-off			(132)
Recoveries of loans previously charged-off	1	1	2	2
Net loans charged-off	1	1	(130)	2
Provision for credit losses	531	162	199	177
Allowance for Credit Losses, ending balance	6,003	4,189	6,003	4,189
Individually evaluated for impairment	500	350	500	350
Collectively evaluated for impairment	5,503	3,839	5,503	3,839
Real Estate Mortgage - Residential [Member]
Allowance for Credit Losses, beginning balance	734	1,106	944	1,284
Recoveries of loans previously charged-off	1	1	3	3
Net loans charged-off	1	1	3	3
Provision for credit losses	22	(26)	(190)	(206)
Allowance for Credit Losses, ending balance	757	1,081	757	1,081
Individually evaluated for impairment
Collectively evaluated for impairment	757	1,081	757	1,081
Construction - Commercial And Residential [Member]
Allowance for Credit Losses, beginning balance	18,742	17,356	18,492	16,487
Loans charged-off	(517)		(517)
Recoveries of loans previously charged-off	35	342	95	345
Net loans charged-off	(482)	342	(422)	345
Provision for credit losses	391	(971)	581	(105)
Allowance for Credit Losses, ending balance	18,651	16,727	18,651	16,727
Individually evaluated for impairment		350		350
Collectively evaluated for impairment	18,651	16,377	18,651	16,377
Home Equity [Member]
Allowance for Credit Losses, beginning balance	699	1,088	770	1,328
Recoveries of loans previously charged-off	10	2	127	3
Net loans charged-off	10	2	127	3
Provision for credit losses	(36)	126	(224)	(115)
Allowance for Credit Losses, ending balance	673	1,216	673	1,216
Individually evaluated for impairment		90		90
Collectively evaluated for impairment	673	1,126	673	1,126
Other Consumer [Member]
Allowance for Credit Losses, beginning balance	335	305	140	160
Loans charged-off		(3)		(66)
Recoveries of loans previously charged-off	5	5	8	12
Net loans charged-off	5	2	8	(54)
Provision for credit losses	(9)	(6)	183	195
Allowance for Credit Losses, ending balance	331	301	331	301
Individually evaluated for impairment	80	52	80	52
Collectively evaluated for impairment	$ 251	$ 249	$ 251	$ 249

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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Amount, after recoveries, of loans and leases that have been written-off.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of expense related to estimated loss from loan and lease transactions.

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